Liquid diffuser liquids, particularly of the type commonly known as “sprinklers” are known to be used in irrigation systems for distributing water or other fluids, particularly for large lands.
Typically, diffuser devices have a support frame which is designed to be connected to the hydraulic system and has a nozzle for directing the liquid jet to a specially shaped diffusion plate.
The latter is in turn mounted to a rotating stem, which is connected to the stationary part of the frame and is rotated under jet pressure.
A commonly recognized drawback of prior art devices is the difficulty of controlling the rotation speed of the plate to obtain as wide and uniform a jet as possible.
Furthermore, in these devices, a considerable part of the peripherally projected liquid is atomized due to the diffuser motion and evaporates before reaching the soil. Evaporation loss may even reach 30% in particularly dry environments.
In an attempt to overcome these drawbacks, various liquid diffuser solutions have been developed, which address some of these problems.
U.S. Pat. No. 5,439,174 discloses a diffuser device having a rotary deflecting member held within a hollow body and supported thereby via a universal joint.
The rotating member is driven into rotation by a gear assembly composed of a pair of facing gears integral with the rotating element and the hollow body respectively.
While this solution ensures rotation of the diffuser at any speed, it cannot control and limit the rotation speed of the rotating member and hence instantly adjust the water jet.
Furthermore, the presence of a gear assembly increases construction and assembly complexity and costs.
Also, since the hollow body is totally open, foreign bodies, such as sand or dust, may infiltrate the areas that support and contact the rotating member, and cause irregular operation, possibly leading to total blockage.
U.S. Pat. No. 5,588,595 also discloses a diffuser device in which the joint for connecting the rotating element with the fixed containing element is a ball bearing assembly.
While this prior art solutions provides a simpler diffuser, it still cannot adjust the rotation speed and cannot prevent abnormal operation and blockage from occurring as a result of foreign bodies penetrating the areas that support the mutually contacting parts or against which they slide.